This revision is based off the way of the sun soul with buffs to make it feel less underpowered

Changes:
-Changed over scaling to Wisdom on the Sun Bolts
-Added Dancing Lights cantrip
-Changed the Searing Arc to be Radiant Waves with a Dex save for half damage
-Added a 6th level defensive option
-Added 1d6 damage to the Sunbursts
-Gutted and reworked the capstone ability

Sun Shot

Starting when you choose this tradition, you hurl bolt empowered by the sun

You gain a new attack option with a range of 30 that deals radiant damage equal to your martial arts die plus your wisdom modifier.

You can also spend 1 ki point to make this attack twice as a bonus action

Orbs of Radiance

At 3rd level you can cast the Dancing Lights cantrip without the material component 

Searing Wave

Once at 6th level, you can channel ki into searing waves of energy.
Immediately after you take the attack action, you can spend 2 ki points to unleash a 15ft cone of radiant energy as a bonus action.
All creatures in the cone must make a dexterity save to take half damage. 
The damage is 3d6, but can be scaled up by 1d6 for every additional ki point spent. 
The max number of ki points that can be spent on this is equal to half your monk level

Solar Flare

Also at 6th level, you gain the ability to summon a defensive flare
As a reaction, you can project light between yourself and an attacking creature, who is within 30ft,  imposing disadvantage to the attack. Attackers that cannot be blinded are immune

Miniature Supernova

Upon reaching 11th level you gain the ability to hurl radiant grenades.

As an action, you hurl a radiant orb at a point within 150ft. Every creature, not behind total cover, within 20ft of that point, must make a con save to take half damage.

 The damage is 3d6, but you can spend up to 3 ki points to increase the damage by 2d6 per ki point.

Solar Warrior

At 17th level you gain the ability to transform into a warrior of the heavens once per short rest.

You can spend 10 ki points to infuse your soul with the power of the sun granting a boost to your abilities for 10 minutes. While maintaining concentration, you gain the following benefits until the spell ends:

-Gain temp hit points equal to 5 times your dexterity or wisdom mod plus your monk level. They are lost when the spell ends.
-Deal an extra 2d12 radiant damage when dealing damage with a monk weapon or radiant spell
-Gain advantage to strength checks and constitution saves
-Gain a flying speed equal to your walking speed
-Gain an aura of bright light that extends out in a 30ft radius, with dim light for another 30ft